Der Radiologe
-
Total knee arthroplasty (TKA) is one of the most successful operative procedures over the last decades in orthopedic surgery; however, some patients suffer from pain, limited range of motion, instability, infections or other complications postoperatively. Patellofemoral pain (PFP) in particular is a common problem after TKA and often necessitates revision surgery. ⋯ The authors suggest that patients with PFP should be categorized after basic diagnostic measures according to the suspected diagnosis: (1) tendinosis, (2) mechanical reasons, (3) intra-articular non-mechanical reasons and (4) neurogenic/psychiatric reasons. Efficient application of special diagnostic measures and further therapy is facilitated by this classification.
-
Patellofemoral instability remains a diagnostic and therapeutic challenge due to its multifactorial genesis. The purpose of imaging is to systematically analyze predisposing factors, such as trochlear dysplasia, patella alta, tibial tuberosity-trochlear groove (TT-TG) distance, rotational deformities of the lower limb and patellar tilt. ⋯ Diagnosis of acute and often overlooked lateral patellar dislocation can be established with magnetic resonance imaging (MRI) because of its characteristic patterns of injury. Damage to the medial patellofemoral ligament (MPFL) has a significance just as high as the predisposing risk factors in relation to the cause of chronic instability.